Interface circuits for bidirectionally transmitting data between an operating device for a lamp and a bus are fundamentally known. Such an interface is known, for example, from U.S. Pat. No. 6,762,570 B1. FIG. 4 of said document shows a circuit having two optocouplers for transmitting and receiving data. The bidirectional transmission is controlled by a microcontroller 102, this microcontroller having, on the one hand, connections for receiving data and, on the other hand, separate connections for transmitting data. In the operating device, a plurality of pins are assigned to the bidirectional communication on the intelligent circuit in the form of the microcontroller.
Accordingly, the aim of the invention is to provide a simplified interface circuit.
The object of the invention is achieved by the features of the appended independent claims. Advantageous refinements and developments of the invention emerge from the dependent claims.